scripts/rpc.py: allow empty lines when executing script

This is a bit more flexible in case script accidentally
has an extra newline at the end of the rpc.py input.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I1ebf08681e5900a4817712c7b62e4d5c21d43e54

Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/453956
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

scripts/rpc.py

@@ -1784,6 +1784,8 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse
 
     def execute_script(parser, client, fd):
         for rpc_call in map(str.rstrip, fd):
+            if not rpc_call.strip():
+                continue
             args = parser.parse_args(shlex.split(rpc_call))
             args.client = client
             call_rpc_func(args)